Bone transplantation has been a common surgical procedure for a number of years. In this regard, conventional bone transplantation typically involves removing a bone plug from another site from the same patient (i.e., an autograft) and then inserting the plug at a different site in need of the same. Transplantation of bone from another donor (i.e., an allograft) has also been used where autograft bone is not available. Allograft bone is processed in several ways and is available in solid, paste, or particulate matter.
In recent years, surgeons have been using osteoarticular autografts to repair small defects in the femoral condyle. Small plugs are taken from remote areas of the condyle and transplanted to areas which have defects and are more critical. Osteoarticular allografts, however, have not typically been used because osteoarticular cartilage cells do not survive the freezing or cryopreservation process. Recent advances in preservation of fresh articular cartilage have, however, made the use of osteoarticular cartilage allografts more common.
Instrumentation for bone plug transplantation has yielded plugs of a specified diameter. See in this regard, U.S. Pat. Nos. 5,782,835 and 5,919,196, the entire content of each being incorporated expressly hereinto by reference. The surface characteristics of autograft plugs have not been a consideration in selection or harvesting. In transplanting articular allografts, however, these surface characteristics are critical. In order for the allograft to be successful, the surface of the transplanted plug must have the same contour as the excised osteochondral tissue. If this contour is not correct, the articular surfaces of both the femur and tibia are at risk for damage.
According to the present invention, osteoarticular allografts are transplanted by techniques which ensure substantial surface contour matching. Broadly, the present invention is embodied in surgical techniques whereby a plug from an osteochondral allograft may be transplanted to a cavity site which remains after a condylar defect is removed from a patient's condyle. In this regard, the present invention essentially includes placing an osteochondral allograft in substantially the same orientation as the patient condyle, and then removing the transplantable plug therefrom and forming the cavity site in the patient condyle while maintaining their relative same orientation. In this manner, the surface of the transplanted plug is matched to the contour of the excised osteochondral tissue.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.